WO 98/01315 discloses a fuel container that includes two plastics material shells. To maintain a precise distance between the two shells during welding thereof, the shells each have a spacer. The spacers form stops during the joining of the two shells. Because the spacers are not stops which are welded together, they cannot transfer any tensile forces, and therefore are not effective when overpressure prevails in the tank
A fuel container that includes two plastics material shells is known from U.S. Pat. No. 6,338,420, of which the shells are braced by an internal column against curvature caused by an overpressure or vacuum. For this purpose, the column is either deformable in the longitudinal direction thereof, or includes two parts which can slide one inside the other in an abradant manner. It is not disclosed, and is also difficult to imagine, how the column or parts thereof are positioned during assembly, and thus, welded to the shells so that they can also take up significant tensile forces. In the two-part embodiment, practically no tensile forces are transferred and it is doubtful whether, and how, the two parts come to be arranged one inside the other when joining the two (non-transparent) shells.